1. Field of the invention
The present invention relates to a laminating film for forming a protective layer on a printed matter and a method using this laminating film. Particularly, it relates to a laminating film and a laminating method for hot-press-bonding to the printed matter the protective layer formed on a substrate and then stripping off the substrate to form the protective layer on the printed matter.
2. Related Backgroud of Art
Hitherto, methods have been widely used in which a transparent resin layer coated on a heat-resistant substrate is hot-pressed-bonded to an output print of electrophotography and ink jet. As disclosed in Japanese Patent Application Laid-Open No. 6-91767, for example, there are also methods in which a laminating film having a protective layer is bonded to the printed matter, and the protective layer alone is transferred onto the surface of the printed matter. In this case, for methods for coating the protective layer on the laminating film substrate, usually a coating having a polymer dissolved in a solvent is applied, or a coating with resin particles dispersed in a solvent is applied as an emulsion, and is dried.
On the other hand, Japanese Patent Application Laid-Open No. 2000-44901 discloses a technique of incorporating an ultraviolet absorbing molecular structure in a polymer constituting a protective resin layer to form a chemically stable ultraviolet absorbing layer. The resin disclosed as an embodiment in this patent publication remains solid on the polycarbonate substrate, but on the paper substrate, the resin of such formulation cannot bear paper stretch during moisture uptake, resulting in cracking.
In the conventional arts described above, two mutually contradictory requirements that only the protective layer bonded to the printed matter should be able to be cut accurately at the edge of the printed matter and that the protective layer should not be cracked with enlargement in size of the printed matter due to moisture uptake can not be satisfied at the same time.
An object of the present invention is to provide a laminating film such that when a laminating film and a printed matter are laminated together and a heat resistant substrate is then removed, a protective layer is cut accurately at the edge of the printed matter, and the protective layer is not subjected to cracking even if the printed matter takes up moisture, and a laminating method using this laminating film.
The laminating film of the present invention has at least a surface layer and an adhesive layer coated on a substrate, in which the above described surface layer is formed by applying coatings prepared by mixing together at least two types of emulsions.
Also, the laminating method of the present invention, which uses a laminating film coated with coatings prepared by two or more types of emulsions which are comprised of emulsion polymers different in glass transition temperature from each other, comprises a step of press-bonding the above described laminating film to a printed matter at a temperature higher than or equal to the glass transition temperature of the emulsion polymer with relatively high glass transition temperature, and a step of separating the substrate of the above described laminating film from the above described printed matter thereafter.